Piston.



'". W. JACOBS.

PISTON.

APPLICATION FILED JAN. 13, 1911,

Patented Feb. 23, 1915.

HENRY W. JACOBS, OF TOPEKA, KANSAS.

PISTGN.

specification of Letters Patent. 'Patented peb, 239 1915,

Application led January 13, 1911. Serial LNo. 602,425.

to animprovement in pistons lfor internal.

combustion'engines; the object being to provide a piston which maybe made as lightv in weight as possible and at the same'time possess the requisite strength to adapt it fon use more especially -in connection with a ourcycle internal combustion engine; the piston being provided with a non-leakable packing. Y 1 Y A further object of my invention is to provide the piston with means Jfor air cooling the piston, as will Vmore fully appear from the following detailed description.

In the drawings: Figure l illustrates my improved piston Within a horizontal air cooled cylinder, the piston and cylinder being shown inlvertical cross section with the piston rod omitted. Fig. 2 is a horizontal cross section taken through the piston on `the line a-a of Fig. l. Fig. 3 is a plan-view of the piston head looking vat it .from the crank side, with the cooling iins omitted and showing the slots into which'they are inserted.

Fig. 4 is aperspective viewof thecbinposite packing, the different-rings or parts thereof being shown slightly separated in'order to more clearly illustrate their construction.

5 is a plan view of one of fthecooling fins inserted in the piston'head.

I have illustrated my improved'piston inserte'd-in what is known as a horizontal'air cooled cylinder A,in Fig. l; the cylinder being shown providedV with heat-radiating portions or `dns. My improved piston consists of the cylin-v drical guide portion 1,'preerably made ofV cast iron; :the spherical head 2,pref'erably made ofv'steehand the inwardly proJecting ns 3. The cylindrical guide 1 is beveledT or taperedfat itsjone end so as toprovide the reduced and threaded portion b, whilethe head 2 isprovided with the. reduced annular portion c which is threaded to take into the 'threaded portion of the cylindrical guide l.

The' head2 adjacentlto the reduced portion c is beveled in the opposite direction rfrom the kbevel or the guide l, thereby providing a socket or pocket for the reception of lthe packing. f

I prefer to employ a composite packing comprising-the three members or split rings Ll, 5, and 6, preferably made of cast iron. Themembers or rings 4 and 6 are preferably .split so as to provide the overlapping portions CZv and e and al and e', see Fig. 4; while the intermediate member 5 is preferably 'split Iin the diagonal manner-clearly shown in Fig. 4. The intermediate member or split ring 5 is provided at its inner circumference with the flange portion f extending to opposite sides of the main or body por.

cev

tion thereof, .so as to form an inverted T Y in cross section, as clearly shown 'in Figs. l and 2; the members or rings 4 and 6 being intended to take against the body portion of the ring or member 5 and about kthe flange-portion 'f as clearly shown in the drawing, Figs. l and 2; the assembled or composite packing being of trapezoid vshape 'in cross section, see Figs. l and 2.4v By employing a composite packing, of the characterdescribed, composed of separatei split rings, it is apparent that the joints in the respective members or rings may be arf ranged atdiferent points on the circumference of the composite packing, Vthereby enabling the making of 'a comparative gas or vapor 'tight joint. The assembled 0r composite packing is placed inthe socket or pocket intermediate of the body of the cylindrical guide 1V and the lhead 2 as clearly shown. In operation, the spherical head 2is subjected to pressure during the compres-y Y ysionand expansion strokes, which tends to expand it slightly, thereby compressing the packing and compellingr to expand lso that a gas or vapor tight Joint is formed;

whiley during the 'expansion and suction strokes of the piston, vthe pressure is relieved from the spherical lhead 2, allowing it vto contract slightly, and'thus in turn releasing the packing, permitting it to conj tract. This contraction and release of the packing will of course reduce the piston friction toa minimum.

I have shown :and described the head 2 taking'into the reduced end of the guide l, for'the reason that the expansion of steel is greater than that of cast iron; the method of construction shown and described therefore Aenables aperfectly tight union being madebetween the guide and head. Furthermorefwith the piston guide 1 and packing rings 4, 5, and 6 made of cast iron and the spherical head 2 of steel, lthe greatestv strength and, atthe same time, lightness are obtained. By thus constructing the devlce,

itis apparent that the frictional surfaces will be of cast iron, while the head, where strength is mostly desired, will be of steel,

The inside or concaved surface of the headl 2 is providedwith the additional radiating surface or means composed of the fins 3, of

which any suitable number may be ,em A

i y ployed. I prefer to arrange these ins 3 'in l of machined steel.

the radially extending manner illustrated in- Figs. 1 and-2; and ,they are preferably made These fins or cooling members may either'be cast integral with the head 2 or welded thereto; 'I prefer,

however, to provide vthe head 2 with theradially extending slots 7, see Fig. 3, intoV which the cooling members or fins 3 are 1nserted and .preferably autogenously welded f in place. The fins 3 are 'preferably made'of the form or'shape more clearly illustrated in Fig. 5, so' as to adapt them to the contour of]V the inner circumference of the guide 1;

- The head 2-'and the cooling members or iz.; fins 3 arepre'ferably machined, and the fins preferably secured in' place. as above 'de scribed, although they may be secured in any other suitable manner. jThis method of construction insures vuniformity and lightness f which are quite'essential in high speedinternal combustion engines. By providing the cooling members or fins on the inside or concaved face of thehead 2, it is evident that the heat' will be radiated'or carried ofl:`- if in t and i toward the opposite end of theA guldel.

In constructing the concavoconvex circular head 2 and. ther end of the cylindrical v guide 1 with the beveled-.surfaces as previ- 3 ously described, it isapparent that a wedgeshape circumferential; groove is provided.`

' The outer side surfaces of both rings'4 and are made sloping or beveled to 'correspond with the'beveledor: 'sloping'rsidewalls of the",

1 i? grooveas is clearly'shown in Figs. 1 and 2, and by the top 4surface 'of the ring 'in Fig.' 4. -It is apparent from the-l construction shown and described, that the in? termediate vmember or ring 5 of the packing',

when the parts are assembled and -in place,-

supports the otherm'embers or rings and 6.

By constructing my 'improved piston inI the manner shown and described, it enables the samebeing machined all over, thereby insuring uniformity throughout in addition' ,to great strength and lightness.

I have shown the' piston-head provided wlth ramiicatio'ns or protruding surfaces on Its one side and these surfaces provided with f i openingstherethrouglnbut it is apparent that the character and method of forming these radiating surfaces, as Well as a number .shown and described, 'but l s of minor details, may be altered'without departing from the spirit of my invention, and I do not wish to be understood therefore* as Ating myself to the exactgjconstructlon What I claim as myinventioin,A

` to secure by Letters Patent is 1. .A compositainetallicpiston for Iinternal combustion engines, comprising a cylindrical guide, a coneavo-conyexqcircularhead,`fa11d a,- packing-located, at 4a point intermediateof the guidev and;hea`dthe head -being con'i'posed;l of lmetal having-- greater epansibility 'than' vthatoftheguide, the relation between the ,head .and "guide being such that .the eirpanf sion `and'contraction of-thehead will corps.

trolthefrictional relationbetween the ing and thev Walls ofthe cylinder.v f f ;2., =A-piston for internal combustion en-- g1nes comprising a l,cylindrical guide, a spherical head of greater expansibility than..

the guide, adapted to take .into one` end of the guide, and a composlte packing ariranged about-the' juncture vof thehead and guide, the relation betweenthe pistonand:

sf y

loef

the'head portionand-the walls of the cyliider may vary duringy the respective; strokes Qflthe piston without affecting ,the connec-` the guide portion' andthe head'V tion `between portion'.` .A 1 4.V A compositeF piston for internal com -v bustionengines, comprising -a hollow guide lot port-ion, and a concave-convex circular head ,portion of'metalpossessing relatively greater expansibilitythan that ofthe guide portion,

the.. head portionbeing adapted to *extend .i

into the; guide portion land so arranged 'that 'the frictionalrelationbetween thehead portion Vand Athe .Wallsof the cylinder 1 may*l `vary during the-:respective strokes `-of-'the piston tions maintained. A f 5. 'Al two-.partfpistonf for' internal -rcombustion Vengineaz-.comprising a cylindrical andka tightrconnectionbetween the two por.- v

guide-ofgcast -iron, anda spherical head of steek-"said Vparts having reduced screwthreaded portionsarranged to screw into pansion'- without afecting' the joint.

GVA composite piston' for internal combustion engines, comprising` a hollow guide-l portion', andra spherical head portion of metal possessing greater 'expansibility than that-of the guide-portionfandz arranged to .each other so. as to permit of unequal ex.- v

'portion of metal possessing greater exdissipate heat toward the opposite end of the guide-portion, said portions being so secured together that'the frictional'relation between the head-portion and walls of the cylinder may vary during the respective sj lies of the piston and a tight connection tween said portions be maintained.`

7. A composite piston for internal combustion engines, comprising a cylindrical guide-portion, and a concavo-convex headpansibility than that of the guide-porl tion, the head-portion being so secured to the guide-portion that the frictionalrela .tion between the head-portion and the walls of the cylinder may vary during the respective strokes of the piston and a tight connection betweenthe guide-portion and head portion maintained, the concaved side of the head-portion being provided with heat-dissipating. portions.

8. A. composite piston for internal combustion engines, comprising a hollow guide portion, and a concavo-convex head ,portion of metal possessing greater expansibility than that of the guide portion, the head portion being so secured to the guide portion that the head portion may expand and contract during the respective 'strokes of the piston and maintain a tight connection with the guide portion, the concaved side of the head portion being provided with radially ar# ranged heat-radiating portions. r 9. A piston `for internal combustion engines, comprising a hollow guide member, and a concavo-convex head member, the 'adjacentends of the two members being reduced so as to prov'ide a packing receiving groove, the head member being of metal possessing relatively greater expansibility 'than that of the guide member and so se cured thereto that the frictional relation between the head member and the walls of the cylinder may vary during the respective strokes of the cylinder while the connection between the two members is maintained, the concaved face of the head member being provided with radially extending heat-radiating portions.

HENRY JACOBS.

Witnesses FRANK MITCHELL, H. Lamm. 

